As the technology evolves, a speed of a comparator becomes increasingly high, and power consumption of a comparator is dynamic; therefore, an analog to digital converter that is based on a comparator structure becomes increasingly advantageous.
However, a comparator features metastability. When two extremely similar signals are input to the comparator, due to a limited amplification multiple of the comparator, the comparator cannot distinguish electrical levels of the two input signals for a long time, and therefore outputs an intermediate electrical level. In this case, a metastable state occurs. Once a metastable state occurs on a comparator, an analog to digital converter that is based on a comparator structure may become invalid or deteriorate in performance, and cannot operate normally.